Circuit-interrupter.



J. N. MAHONEY & H. G. MAcDONALD.

CIRCUIT INTERRUPTER.

APPLICATION FILED NOV. 2a. 1913.

Patented Sept. 17,1918;

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INVEN 085 f 7 Q v ATTORNEY J. N. MAHONEY & HLG. MAcDONALD.

CIRCUIT INTERRUPTER.

APPLICATION FILED NOV. 28,1913.

Patented Sept. 17, 1918.

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UNITED STATES PATENT oEEIcE.

JOSEPH N. MAHONEY AND HOWARD G. MACDONALD, 0F WILKINSBU'RG,PENNSYLVANIA,

ASSIGNORS TO WESTINGHOUSE ELECTRIC AND MANUFACT CORPORATION OFPENNSYLVANIA.

CIRGUIT-INTERRUPTER.

To all whom it may concern:

Be it known that we, JosEPH N. MA- HONEY, a citizen of the UnitedStates, and a resident of Wilkinsburg, in the county of Allegheny andState of Pennsylvania, and HOWARD G. MACDONALD, a citizen of the UnitedStates, and a resident of Wilkinsburg, in the county of Allegheny andState of Pennsylvania,have invented a new and useful Improvement inOircuit-Interrupters, of which the following is a specification.

Our invention relates to electric-circuit interrupters and particularlyto operating mechanism for the same.

One object of our invention is to provide an operating mechanism thatrequires a minimum space and which is adaptable to operate a pluralityof circuit interrupters.

Another object of our invention is to provide a combined acceleratingand retarding device for operating in combination with the operatingmechanism.

In the prior art, multi-pole circuit interrupters have usually beenprovided with a plurality of operating electromagnets, uneconomicallylocated with respect to the space occupied by the same.

According to our present invention, we provide a circuit interrupterhaving a single compact operating mechanism which may be located infront of any two adjacent poles of the same, and we also provide acombined accelerating and retarding device which insures a rapidlyopening circuit breaker that is free from the jars and shocks whichusually occur in devices of this kind. The entire mechanism of ourinvention is compact, simple and durable in construction, and itsadjustable features make it especially adaptable to multipolar circuitinterrupters.

In the accompanying drawings, Figure 1 is a front elevational view of acircuit interrupter embodying our invention. Fig. 2 is a side view,partially in elevation and partially in section, of the circuitinterrupter shown in Fig. 1. Fig.3 is a front elevational view of anoperating mechanism embodied in our invention. Fig. 4 is a side View,partially in section and partially in elevation, of the operatingmechanism shown in Fig. 3, and Fig. 5 is a sectional View of anaccelerating and retarding device embodied also in our invention.

Specification of Letters Patent. Patented Sept. 1"? 1918 Applicationfiled November 28, 1913.

Serial No. 803,614.

Referring to I the drawings, the circuit breaker here shown comprises,in general,

- bers 8; mam movable contactmembers 9,

and auxiliary movable contact members 10, mounted upon the ends of abridging member 11 and arranged for cooperative engagement with theabove mcntionedstationary contact members 7, and an operating rod 12located in a relatively central position with respect to the conductingterminal members 8 and connected" to the bridging member 11 by anysuitable means. The conducting terminal members 8- are insulated from asupporting base member 13 by insulating bushings 14:. A receptacle 15,containing oil in which are immersed the cooperative contact members, isattachedto an expansion chamber 16 suspended from the underside of thesupporting base member 13.

The single pole circuit breakers 1, 2 and 3 severally comprise a. crankarm 17 keyed to a shaft 18 which is common to all of the said circuitbreakers. One end of the crank URING COMPANY, A

arm 17 is pivotally connected to one end of a link 17, the other end ofwhich is pivotally connected to one end of a bell crank lever 19. Thelever 19 is pivotally mounted by a detachable frame 26 and comprises, in

detail, an electromagnet 27 having a winding 28, and a movable coremember 29 which is operatively connected, by a link 30, to a Y crank arm31 that is keyed to the shaft 18.

1 The core member 29 is provided with a tightly fitting pliable washermember 29 'upon its lower end, for reasons hereinafter set forth. Asaddle link member 32 is pivotally attached to the link by a pin 33. Atan intermediate point on the link member 32, is pivotally attached oneend of a. guide link 34, the other end of which is pivotally mountedupon a projection 35 on the frame 26. The link 32 is provided with aneye 36 at its upper end to receive a latch mem ber 37 that is pivotallysupported by a pin 38 mounted between trunnion supports 39 on the frame26. The latch member 37 is operated by either of two electromagnets 40and 41 having movable core members 40 and 41, respectively. The inactivepositions of the core members 40 and 41 may be adjusted by means ofthumb screws 42 placed below the respective electromagnets.

We provide an auxiliary circuit controlling device having a pivotallymounted knife blade member 43 which is pivotally attached to one end ofa link 44, the other end of which is pivotally connected to the link 32.Two contact members 45 and 46 are alternately engaged by the knife blademember hereinbefore mentioned, and they are electrically connected to anindicating means (not shown) for indicating the open and closedpositions of the circuit breaker.

The shaft 18 is supported by a plurality of bearings 47 and it extendsacross the front portion of each single-pole circuit breaker, for thepurpose of transmitting the movement of the movable core member 29 ofthe electromagnct 27 to each of the breakers.

The accelerating and retarding device 5 comprises a cylindricalstructure 48 mounted on a frame 49 and adapted to receive a powerfulhelical accelerating spring 50 which acts against one end of thecylindrical structure 48 and against a tightly fitting piston 51 toretard the action of the spring toward the end of its expansion by adashpot action. The piston 51 is attached, by any well known means, to apiston rod 52 having a hook on its lower end which operatively engages apin 53 that projects from one of the several crank arms 17.

The accelerating and retarding dev ce 5 and the main operating device 4may be located in any desired positions with respect to the individualsingle-pole circuit breakers.

Assuming the contact members to be in the positions shown in Figs. 1 and2 and that an overload or a short circuit occurs upon the circuit whichthe circuit breaker is protecting, the operation will be as follows:

An increased current will traverse the windings of the electromagnets 40and 41' that are connected in open delta relation to a three phasecircuit (not shown) and cause them to draw the movable core members 40-and 41 upwardly to operate the latch member 37 which is restrained fromoperating otherwise by the force of ravity and a spring 54. The latch 37re eases the link member 32, which normally cooperates with a guide link34 to prevent upward movement of the link 30. The link member 32 movesoutwardly and upwardly by reason of the forces transmitted to the samefrom the accelerating spring 50, acting through the shaft 18 and thecrank 31. Rotative move ment of the shaft 18 operates the crank arms 17which transmit their motion, through the links 17", the bell cranklevers 19, the links 21 and the levers 22 to the rods 12 to effectdisengagement of the movable contact members 9 and 10 from thestationary contact members 7 with great rapidity. Near the end of themovement of the contact members 9 and 10, the shock resulting from therapidly accelerated motion is absorbed by the piston 51 by reason of itsaction against the air being compressed in the lower part of thecylindrical structure 48. When the link 32 moves upwardly, the knifeblade member 43 engages the contact member 45 to complete a circuitthrough an indicating device (not shown) to indicate that the breaker isin its open position.

The operation of closing the breaker is similar to that above describedin that, current traverses the winding 28 of the electromagnet 27,thereby attracting the movable core member 29 with such force as to moveit downwardly andti'ansmit its motion through the link 39 and the crankarm 31 to the shaft 18. The rotative movement of the shaft 18 causes thecrank arms 17 to move downwardly, and they transmit their downwardmotion, through the links 17 the bell crank levers 19 the links 21 andthecurved pivotally mounted levers 22, to the links 25. which moveupwardly and carry the rods 12 and the movable contact members 9 and 10to effect their engagement with the stationary contact members 7. Therotative movement of the shaft also causes the pin 53 to move downwardlyto compress the spring 50. The core member 29 will be retarded towardthe end of its downward movement by compressing the air in the closedstructure constituting the stationary core member of the electromagnet27.

lVhen the link 30 moves downwardly, the 1115 link 32 that, is pivotallyassociated with the same moves inwardly and downwardly to engage thelatch 37 and to act as a restraining toggle joint to preventdisengagement of the contact members until the latch mem- 120 ber 37 isagain tripped to release the operat ing mechanism. VVhen the link 32moves downwardly, it effects an engagement between the knife blademember 42- and the stationary contact member 46 to complete 125 anauxiliary circuit for indicating the closing of the breaker, ashereinbefore described.

Since various structural modifications may be efiected within the scopeof our invention, we desire that only such limitations 180 shall beimposed as are set forth in the appended claims.

We claim as our invention:

1. An operating mechanism for a circuit interrupter comprising a basemember, an operating electromagnet, an operating shaft having a crankarm thereon, a link for opcratively connecting e electromagnet to thecrank arm, a lever arm operatively connected to the crank arm, a latchfor the lever arm and means for so guiding the lever arm that it movesdownwardly away from the base member and then toward the base memberwhen the electromagnet is actuated.

2. An operating mechanism for a circuit interrupter comprising a basemember, an operating means, an operating shaft having a crank armthereon, a lever arm connected to the crank arm, means for connectingthe operating means to the crank arm, a latch member and means for soguiding the lever arm that it moves do nwardly away from the base memberand vhen toward the base member when the operating means is actuated.

3. An operating mechanism for a circuit interrupter comprising a basemember, an operating electromagnet, a rotatable shaft having a crank armthereon, a link for 0peratively connecting the movable member of theelectromagnet to the crank arm, a latch member, a latch arm connected tothe crank arm and adapted to cooperate with the latch member, and meansfor so guiding the latch arm that it moves downwardly away from the basemember and then toward the base member when the electromagnet isenergized. 4. An operating mechanlsm for a 01mm interrupter comprising abase member, an

operating electromagnet, a rotatable shaft operatively connected to theelectromagnet, a lever arm operatively connected to the shaft, a latchfor engaging one end of the lever arm, and a link member for so guidingthe lever arm that it moves downwardly away from the base member andthen toward the base member when the electromagnet is energized. J

5. An operating mechanism for a circuit interrupter comprising a basemember, an operating electromagnet mounted at the lower end thereof, arotatable shaft operatively connected to the electromagnet, a lever armconnected to the shaft, a latch member for the lever arm, and means forso guiding the lever arm that it moves away from the base member, towardthe base member and toward the electromagnet when the electromagnet isenergized.

6. An operating mechanism for a circuit interrupter comprising a basemember, an operating electromagnet, an operating shaft having a crankarm thereon, a link for connecting the electromagnet to the crank arm, alever arm connected to the crank arm, and means connected between thebase member and the lever arm for so guiding the lever arm that it movesdownwardly toward the electromagnet and away from the base member andthen toward the base member when the electromagnet is actuated.

In testimony whereof, we have hereunto subscribed our names this 24thday of Nov.,

JOSEPH N. MAHONEY. HOWARD G. MAoDONALD. Witnesses JOHN MoKEoHNIn, B. B.HrNEs.

